Explosive connector assembly



July 12, 1966 T. N. BRYLA EXPLOSIVE CONNECTOR ASSEMBLY Filed Feb. 5, 1964 Fig. I

United States Patent O 3,260,202 EXPLOSIVE CONNECTOR ASSEMBLY Theodore Norman Bryla, Glendora, Calif., assigner to Aerolet-General Corporation, Azusa, Calif., a corporation of Ohio Filed Feb. s, 1964, ser. No. 342,720 s claims. (ci. 1oz- 27) My invention generally relates to an explosive assembly, and more particularly to a unitary connector assembly for attaching a fuse member in axial alinement betweeen an explosive initiator and an explosive Without breaking the continuity of the fuse member. In the field of detonation, one practi-ce heretofore employed for det-onating an explosive comprises connecting an initiator to the explosive through an elongated fuse containing an explosive core or a pyrotechnic core. A common problem detracting from the reliability of an attempted detonation of an explosive is caused by the connections between the init-iator and the fuse member and between the fuse member and the explosive which frequently are responsible yfor causing breaks in the explosive core of the fuse member -with consequent inability to detonate the explosive.

An object, therefore, of my invention is to provide a novel unitary connector assembly for securing la fuse member to an explosive initiator in such a-manner as to provide for increased reliability in the detonation of an explosive.

It is another object of my invention to provide a novel unitary connector assembly for securing a fuse member toV an explosive initiator without breaking the continuity of the -fuse member so as to substantially reduce the possibility of a break occurring in the fuse member.

Other aims and objects of my invention will appear from the following explanation thereof.

lIn accordance with the present invention, the connector assembly comprises -a pair of tubular holders adapted to be respectively secured to the opposite ends of an elongated fuse member. Each of the tubular holders is provided with recesses in the opposite ends thereof which are interconnected by an axial bore forming a passage extending longitudinally of the holder. The elongated fuse member has an explosive-transmitting core made from an explosive material or an explosive-metal oxidant encased ina sheath, preferably of lead, the core being surrounded by a casing which may be formed of a plastic-iiberglass material. In `securing the elongated fuse member and the tubular holders together lto form the unitary connector assembly, the fuse member is initially prepared by stripping the casing of the fuse member from the core at the opposite end portions of the fuse member to ex pose the end portions of the core. The ends of Ithe core Iare carefully cut with a sharp knife to prevent deformation of the explosive material thereof so as to insure that the entire periphery of the explosive material is confined within the sheath. Asuitable adhesive material, such as glue or cement, is applied to each of the exposed end portions of the core and to the corresponding recess therefor in each of the tubular holders. The tubular holders are then respectively secured to the opposite ends of the fuse member in inserting each of Ithe exposed end portions of the core vof the fuse member into the axial bore of the tubular holder corresponding thereto for disposing part of the casing of the fuse member within one of the recesses in the tubular holder. The walls of the tubular holder bounding the latter-mentioned recess are then crimped inwardly about the casing of the fuse member. Each of the end portions of the core respectively adjoins the other recess in the tubular holder corresponding thereto. T-he other recess in each of the tubular holders contains an explosive material which is retained in the Patented July l2, 1966 ICC recess by a closure disc. The tubular holders of the umtary -connector assembly may be respectively attached to an explosive initiator and an explosive to dispose the elongated fuse member in connected relation between the explosive initiator and the explosive. In the latter re spect, each tubular holder is provided with an annular collar on which a nut is swivelly carried, the nut being adapted to receive a threaded hollow stud forming part of an explosive initiator or an explosive charge. The hollow stud receives the tubular holder which extends therethrough into a bore provided in the explosive initiator or the explosive. Thus, when the explosive initiator is actuated, the explosive material thereof is detonated to create a detonation wave which is passed to the explosive core of the fuse member and thence to an explosive or pyrotechnic charge secured to the other end of the fuse member. In order to facilitate transfer of the detonation wave from the explosive material of the initiator to the explosive core of the fuse member, the other recess in the corresponding tubular holder may be reduced near the passage very gradually in cross-sectional a-rea in an axial direction as it meets with the passage. S-uch a configuration acts to direct the detonation wave from the explosive initiator toward the passage and the end portion of the core of the fuse member disposed therein.

-F0r a more complete understanding of my invention, refe-rence is made to the following description and the accompanying drawings, in which:

`FIGURE 1 is a fragmentary longitudinal sectional view of a unitary connector assembly in accordance With the present invention; and

FIGUR-E 2 is an elevational view of the connector assembly as secured between an explosive initiator and an explosive.

Referring more specilically to the drawings, the connector assembly comprises Ia pair of tubular holders (12 adapted to be secured to the opposite ends of an elongated fuse member or string igniter 44. Each of the tubular holders .12 is provided with recesses .14, .16 respectively formed in the opposite ends thereof to cooperate with the ends of the holder 12 in defining sockets 18, 20. The recesses 14, '16 are connected by an axial bore or passage 22 extending longitudinally of the holder .12. As shown the recesses 14, 16 are of greater diameters than the diameter of the -bore or passage 22. The walls of socket 20 may diminish in diameter in an axially inward direction to form a conical surface 24 which lies adjacent one end of the bore 22. An explosive material or pyrotechnic charge 26 is disposed in socket 20 and held therein by a closure disc 28. The end 30 of the socket 20 terminates in a radially inwardly directed lip which is secured to the closure disc 28 by suitable means, such as by soldering at low temperatures.

A shoulder 32 and an annular groove 34 are formed on the holder 12 intermediate the ends thereof. A nut 36 provided with threads 40 has an inturned end 38 loosely crimped over the shoulder 32 and extending into the groove 34 so as to be swivelly mounted on the holder 12. The nut 36 is adapted to be attached to an explosive init-iator or an explosive mechanism 42. In the latter respect, the explosive initiator or explosive mechanism 42 is provided with a hollow stud or threaded nipple 43 whi-ch threadedly engages the nut 36 and receives the holder 12 therethrough, thereby connecting the holde-r 12 to the explosive initiator or explosive mechanism 42.

The elongated fuse member or string igniter 44 is provided with an explosive-transmitting core 46 which comprises an explosive material or an explosive-metal oxidant having a sheath such a lead shield 47 disposed seeds-ea there-about for added protection. The medial portion of the core 46 is enclosed by a casing 4S which may be formed of a plastic-iibreglass material. The opposite end portions 49 of the core 46 of the `fuse member 44 extend beyond the casing 48 so as to provide exposed core portions 50 which are respectively received in the bore 22 of the holder 12 corresponding thereto so as to be positioned in engagement with the explosive material 26 in the socket 20 of the corresponding holder 12. To insure a good detonating connection between the core portion 50 and the explosive material 26, the tip 51 of the core portion 50 extends slightly into the socket 2t). An end portion 52 of the casing 48 extends into the socket 18 of the respective holder 12 corresponding ther-eto. Each end of the fuse member 44 is secured within its respective holder 12 by applying a suitable adhesive material 54, such as glue or cement, between the core end portion 50 and the surface of the holder 12 bounding the bore 22; by a suitable adhesive material S6, such as glue or roement, between the casing 48 and the socket 18; and by providing a crimp 58 in the socket 18 to deform the socket 18 into the casing 48 of the fuse member 44.

With reference to FIGURE 2, the connector assembly including the elongated fuse member or string igniter 44 and the tubular holders 12 mounted on each end thereof is secu-red at end A to an explosive initiator 42a and at end B to an explosive 42b to be detonated. When the connector assembly is to be utilized for a detonation event, such as for thrust termination and stage separation in a rocket, the sockets 20 of the two holders 12 are loaded with an explosive material 26a and 26b and the core 46 of the fuse member 44 comprises an explosive material, such as PETN.

When the connector assembly is to be employed for a deflagration event, such as for ignition or for gas generation, the socket 20 at end A of the connector assembly is loaded with an explosive 26a, while the socket 20 at end B is loaded with -a pyrotechnic material 26b, and the core 46 of the fuse member 44 comprises an explosivemetal oxidant composition providing a string igniter material, such as Pyrocore.

Upon -actuation of the explosive initiator 42a, charge 26a, if an explosive material, will be detonated to generate a detonation wave. The detonation wave is conducted along the inner `surface of socket 20 and directed by conical surface 24 to the tip 51 of the core portion S0 which carries the detonation wave further through the fuse member 44 tto .detonate the charge 26h, with the resulting detonation of the explosive 42h. If charge 26h comprises a pyrotechnic material, the actuation thereof generates a conflagration to ignite the component 42h.

Although the foregoing is a description of a preferred embodiment of my invention, the following claims are intended to include those modifications and variation-s that are within the spirit and scope of my invention.

I claim:

1. A connector assembly for attaching an initiator to a fuse member provided with a casing and a transmitting core extending hrough the casing and having an end portion extending therebeyond comprising, in combination, a holder provided with a longitudinally extending passage and sockets at its opposite ends lconnected by the passage, said casing lbeing secured in one `of said sockets with said end portion of said core extending through the passage, a charge disposed within the other of said :sockets in engagement with said end portion of said core, and fastener means journaled on said holder and adapted to be secured to the initiator.

2. A connector assembly as set forth in claim 1, including a closure disc secured to the end of said holder on which said other socket isv disposed for closing said other socket to retain the charge within said other socket.

3. A connector assembly as set forth in claim 1, wherein said other socket is provided with an Iinternal diameter greater than that ,o f the passage and with an inwardly tapering conical bottom wall portion joining said other socket with the passage.

4. A connector assembly as set forth in claim 1, Wherein said holder is further provided with an external shoulder having an annular groove adjacent thereto, and said fastener means comprises a nut having an inturned end loosely crimped over said shoulder and into the annular groove to be journaled on said holder.

S. A connector assembly for attaching an explosive to a fuse member having a casing and a transmitting core disposed therein, said `core having an end portion extending beyond said casing, a tubular holder having recesses formed in its opposite ends and an axial bore connecting the recesses, said end portion of said core -being received within the bore of said holder, an external shoulder formed on said holder, an adhesive material interposed between said end portion of the core and the surface of said holder bounding the axial bore to secure the end portion of the core in the bore, said casing being partially received in the recess in one end of said holder, the holder 'being inwardly crimped into said casing adjacent said one end of said holder, a charge disposed in the recess in the other end of said holder, the recess in the other end of said holder being partially defined by an inwardly tapering conical surface extending to one end of the axial bore of said holder to direct detonation waves upon ignition of the charge to insure tiring of the core, a disc secured to the other end of said holder in closing relation to the recess provided therein for covering said charge disposed therein, and a fastener member swivelly mounted about the shoulder of said holder for attaching said holder to the explosive.

6. An explosive connector assembly comprising a fuse member having a casing provided -with an explosivetransmitting core therein, said core including an end portion extending outwardly of said casing, a holder having its opposite end portions provided with recesses and being provided with an intermediate elongate passage interconnecting said recesses, said casing being frictionally seated in the recess provided in one end portion of said holder and said end portion of said core being received through said passage in said holder, an explosive initiating charge contained in the recess provided in the other end portion of said holder, said charge being in communication with said end portion of said core, and means secured to the other end portion of said holder and closing the recess therein to confine said charge in the recess.

7. An explosive connector assembly comprising an elongated fuse member having a casing provided with anr explosive-transmitting core therein, said core including end portions extending outwardly from each end of said casing, a pair of holders for respective securement to the opposite ends of said fuse member, each of said holders having its opposite end portions provided with recesses and being provided with an intermediate elongate passage interconnecting said recesses, the ends of said casing being respectively frictionally seated in the recess provided in one end portion of the holder corresponding thereto, said end portions of said core being respectively received through said passage in the holder corresponding thereto, an explosive initiating charge Contained in the recess provided in the other end portion of each of said holders, said charges being in communication with the end portion of said `core corresponding thereto, and fastener means carried by each of said holders for respectively securing said holders to an explosive intiator and an explosive so that said fuse member is connected therebetween.

8. An explosive connector assembly comprising an elongated fuse member having a casing provided with an explosive-transmitting core therein, said core including end portions extending outwardly from each end of said casing, a pair of holders for respective securement to the opposite ends of said fuse member, each of said holders having its opposite end portions provided Iwith recesses and being provided with an intermediate elongate passage interconnecting said recesses, the ends of said casing being respectively frictiona'lly seated in the recess provided in one end portion of the holder corresponding thereto and said end portions of said core being respectively received through said passage in the holder corresponding thereto, an explosive initiating `charge contained in the recess provided in the other end portion of each of said holders, said charges being in communication with the end portion of said core corresponding thereto, means secured to the other end portion of each of said holders and closing the recess therein to confine said charge in the recess, and fastener means carried by each of said holders for respectively securing said holders to an explosive initiator and an explosive so that said fuse member is connected therebetween.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCES German printed application No. 1,148,925, May 1963.

BENJAMIN A. BORCHELT, Primary Examiner.

R. V. LOTTMANN, V. R. PENDEGRASS,

Assistant Examiners. 

1. A CONNECTOR ASSEMBLY FOR ATTACHING AN INITIATOR TO A FUSE MEMBER PROVIDED WITH A CASING AND A TRANSMITTING CORE EXTENDING THROUGH THE CASING AND HAVING AN END PORTION EXTENDING THEREBEYOND COMPRISING, IN COMBINATION, A HOLDER PROVIDED WITH A LONGITUDINALLY EXTENDING PASSAGE AND SOCKETS AT ITS OPPOSITE ENDS CONNECTED BY THE PASSAGE, SAID CASING BEING SECURED IN ONE OF SAID SOCKETS WITH SAID END PORTION OF SAID CORE EXTENDING THROUGH THE PASSAGE, A CHARGE DISPOSED WITHIN THE OTHER OF SAID SOCKETS IN ENGAGEMENT WITH SAID END PORTION OF SAID CORE, AND FASTENER MEANS JOURNALED ON SAID HOLDER AND ADAPTED TO BE SECURED TO THE INITIATOR. 